scholarly journals Methods for estimating the durability of the needle bearing of the piston head of the connecting rod of a transportation diesel

2021 ◽  
pp. 55-60
Author(s):  
Vadym Mychaylovich Petuhov ◽  
Alexandr Vasilyevich Orobinsky ◽  
Natalya Anatolyevna Aksenova
Keyword(s):  
Diesel Engine ◽  
Service Life ◽  
Test Procedure ◽  
Operating Conditions ◽  
Accelerated Tests ◽  
Connecting Rod ◽  
Design Work ◽  
Engine Operation ◽  
Piston Head ◽  
Rolling Elements

The article presents the results of an experimental study and analytical evaluation calculations to check service life and increase durability of the needle bearing of piston head of connecting rod of a transport diesel engine. The primary reasons for the violation of the nominal operation of the main units of this mechanism have been established. Corresponding recommendations are proposed for carrying out accelerated tests for durability, reducing the thermal loads of the bearing operation and, as a consequence, improving the quality and service life of its entire piston group. Theoretical and experimental methods for determining the nominal life of the needle bearing of the piston head of the connecting rod (PHCR) of a transport diesel engine are proposed. The theoretical methodology allows obtaining reliable values of durability, taking into account the distribution of the working load over the rolling elements, as well as the mobility of the piston pin and sleeve. The performed calculations make it possible to correct and clarify the standard mathematical model for determining the nominal life of the PHCR needle bearing, depending on the distribution of loads on the rolling elements (rollers) under different operating conditions. This experimental technique with an acceleration factor of 10 is based on a twofold increase in the force effect on the elements of the PHCR needle bearing. This was achieved by assembling the bearing using a special technology, which is described in detail in the work. A significant decrease in the thermal effect and a decrease in radial loads on working rollers have been established. For ensure the regular oil supply into bearing during engine operation, a technique was developed to increase the load on the roller in contact zone, which significantly influenced durability and made it possible to conduct accelerated tests with a reliable yield. Its results of operational research and experience in design work correlate and are sufficiently explained by the developed methods, which allows them to be used for the improvement and modernization of connecting rods with needle bearings in PHCR. That is a permission to use these methodic for doing perfect and modern the needle bearing of the connecting-rod piston. Keywords: diesel, test procedure, needle bearing, rollers, piston head of the connecting rod, durability.

Investigations on performance of diesel engine by varying injection timings with design modification on piston crown

2018 ◽  
Vol 15 (5) ◽  
pp. 562-566
Author(s):  
Vijaya K. ◽  
Shailesh Palaparty ◽  
Raghavan Srinivasa ◽  
Ravi Kumar Puli
Keyword(s):  
Diesel Engine ◽  
Injection Pressure ◽  
Combustible Mixture ◽  
Injection Timing ◽  
Connecting Rod ◽  
Design Modification ◽  
Content Type ◽  
Piston Head ◽  
Piston Crown ◽  
Fuel Vaporization

Purpose Investigations are carried out with the aim of improving performance of a diesel engine with the design modification on piston crown to stimulate the uniform combustion by inducing turbulence in the incoming charge. Design/methodology/approach A stirrer is introduced at the top of the piston so as to inculcate more turbulence to the incoming charge by improving the rate of fuel vaporization. Whirling motion is created in the combustible mixture by providing rotating blades on the cavity/bowl of the reciprocating piston head. By putting a simple link mechanism, the oscillatory motion of connecting rod will rotate the blade by an angle of 60°. Findings The investigations are carried out with and without swirl piston at 17.5 compression ratio and 200 bar injection pressure by varying injection timings. Originality/value Finally, the result shows that by using the modified piston, nearly 3 per cent of efficiency increased and 31 per cent of NOx emissions are reduced compared to that of a normal piston with 80 per cent load at standard injection timing.

Startup and Steady-State Performance of a New Renewable Hydroprocessed Depolymerized Cellulosic Diesel Fuel in Multiple Diesel Engines

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Eric Bermudez ◽  
Andrew McDaniel ◽  
Terrence Dickerson ◽  
Dianne Luning Prak ◽  
Len Hamilton ◽  
...  
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Cetane Number ◽  
Operating Conditions ◽  
Engine Operation ◽  
Start Of Injection ◽  
Ignition Quality ◽  
Engine Testing ◽  
Engine Start ◽  
Distillate Fuel

A new hydroprocessed depolymerized cellulosic diesel (HDCD) fuel has been developed using a process which takes biomass feedstock (principally cellulosic wood) to produce a synthetic fuel that has nominally ½ cycloparaffins and ½ aromatic hydrocarbons in content. This HDCD fuel with a low cetane value (derived cetane number from the ignition quality tester, DCN = 27) was blended with naval distillate fuel (NATO symbol F-76) in various quantities and tested in order to determine how much HDCD could be blended before diesel engine operation becomes problematic. Blends of 20% HDCD (DCN = 45), 30%, 40% (DCN = 41), and 60% HDCD (DCN = 37) by volume were tested with conventional naval distillate fuel (DCN = 49). Engine start performance was evaluated with a conventional mechanically direct injected (DI) Yanmar engine and a Waukesha mechanical indirect injected (IDI) Cooperative Fuels Research (CFR) diesel engine and showed that engine start times increased steadily with increasing HDCD content. Longer start times with increasing HDCD content were the result of some engine cycles with poor combustion leading to a slower rate of engine acceleration toward rated speed. A repeating sequence of alternating cycles which combust followed by a noncombustion cycle was common during engine run-up. Additionally, steady-state engine testing was also performed using both engines. HDCD has a significantly higher bulk modulus than F76 due to its very high aromatic content, and the engines showed earlier start of injection (SOI) timing with increasing HDCD content for equivalent operating conditions. Additionally, due to the lower DCN, the higher HDCD blends showed moderately longer ignition delay (IGD) with moderately shorter overall burn durations. Thus, the midcombustion metric (CA50: 50% burn duration crank angle position) was only modestly affected with increasing HDCD content. Increasing HDCD content beyond 40% leads to significantly longer start times.

Paper 5: Compact Long-Life Diesel Engine

1968 ◽  
Vol 183 (2) ◽  
pp. 52-60 ◽  
Author(s):  
S. G. Timoney
Keyword(s):  
Diesel Engine ◽  
Service Life ◽  
Compression Ratio ◽  
Current Status ◽  
Engine Operation ◽  
Variable Compression Ratio ◽  
Specific Output ◽  
Air Supply ◽  
Operation Results ◽  
Variable Compression

Continued development work at University College, Dublin, on the variable compression ratio, two-stroke diesel engine, discussed in earlier communications to the Institution, has demonstrated the ability of this unique design to combine long service life with high specific output. The present paper summarizes the current status of the programme after four years' work. The basic design philosophy adopts a two-stroke cycle and exhaust gas turbocharging to obtain high specific output, and an automatic variable compression ratio mechanism to ensure long service life by controlling piston loads. The paper gives details of the variable compression ratio mechanism including the specification of the various components of which it is comprised. Test results show the response rate of the mechanism relative to changes in engine operation. Results are also given for the engine as operated with various air supply blowers to give characteristics suitable for specific user applications.

Coal–Water Slurry Operation in an EMD Diesel Engine

1988 ◽  
Vol 110 (3) ◽  
pp. 437-443 ◽  
Author(s):  
C. M. Urban ◽  
H. E. Mecredy ◽  
T. W. Ryan ◽  
M. N. Ingalls ◽  
B. T. Jett
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Coal Slurry ◽  
Particulate Emissions ◽  
Development Effort ◽  
Engine Operation ◽  
Coal Burning

The U.S. Department of Energy, Morgantown Energy Technology Center has assumed a leadership role in the development of coal-burning diesel engines. The motivation for this work is obvious when one considers the magnitude of the domestic reserves of coal and the widespread use of diesel engines. The work reported in this paper represents the preliminary engine experiments leading to the development of a coal-burning, medium-speed diesel engine. The basis of this development effort is a two-stroke, 900 rpm, 216-mm (8.5-in.) bore engine manufactured by Electro-Motive Division of General Motors Corporation. The engine, in a minimally modified form, has been operated for several hours on a slurry of 50 percent (by mass) coal in water. Engine operation was achieved in this configuration using a pilot injection of diesel fuel to ignite the main charge of slurry. A standard unit injector, slightly modified by increasing diametric clearances in the injector pump and nozzle tip, was used to inject the slurry. Under the engine operating conditions evaluated, the combustion efficiency of the coal and the NOx emissions were lower than, and the particulate emissions were higher than, corresponding diesel fuel results. These initial results, achieved without optimizing the system on the coal slurry, demonstrate the potential for utilizing coal slurry fuels.

Experimental Study on Anti-Fatigue Damage Structural Design of Diesel Engine Bearings

2012 ◽  
Vol 214 ◽  
pp. 97-101
Author(s):  
Zhen Jie Guo
Keyword(s):  
Experimental Study ◽  
Fatigue Life ◽  
Diesel Engine ◽  
Service Life ◽  
Fatigue Damage ◽  
Working Conditions ◽  
Structural Design ◽  
Connecting Rod ◽  
Main Bearing ◽  
Modern Times

With higher requirements on energy-saving and environmental protection of diesel engine in the modern times, the loads on main bearing and connecting rod bearing of diesel engine are continuously increased, and also working conditions are even more critical. Bearings are the key moving parts of diesel engine, and play an important influence on reliability, service life and other performances of diesel engine. Therefore, the reasons for fatigue damages to its bearings greatly affect fatigue life. In traditional designs, effects of the problem are studied few. In this paper, therefore, this problem is studied for discussing the formation reasons and solutions for it theoretically.

scholarly journals Simulation of a grain harvester threshing drum resource

2020 ◽  
Author(s):  
M. Podolsky ◽  
◽  
I. Lilevman ◽  
О. Lilevman
Keyword(s):  
Service Life ◽  
Computer Software ◽  
Operating Conditions ◽  
Temperature Deformation ◽  
Mutual Arrangement ◽  
Agricultural Machinery ◽  
The Real ◽  
Rolling Elements ◽  
Combine Harvester ◽  
The Difference

Abstract. A significant part of agricultural machinery has a seasonal nature of operation, when sudden failures are extremely undesirable. Proceeding from this, modeling the real operating conditions of bearings in design calculations is relevant, and the novelty of solving the problem lies in the use of modern target computer-aided design programs for this. Research goal. Theoretical determination of the service life of agricultural machinery bearings using targeted computer software, taking into account the real conditions of their operation. Making recommendations of a structural nature to eliminate factors that accelerate bearing wear and increase reliability. Methods. Mathematical modeling of the operating conditions of the bearings of the threshing drum of a combine harvester using the target software. Results. The article presents the main reasons for the premature failure of the bearing units of agricultural machinery, considers the types of methods used to calculate and simulate the operating conditions of rolling bearings, taking into account the specifics of machines and mechanisms in which they are used. On the example of the threshing apparatus of a combine harvester, an evaluation characteristic of the adaptation of the existing computer software applications for the calculation of bearings to the operating conditions of agricultural machinery has been carried out. The most reliable software application was selected, which takes into account the maximum number of factors influencing the service life of the bearing assemblies. The reason for the discrepancy between the values of the calculated and actual service life of the bearing assemblies of the threshing drum of a grain harvester is determined, which is due to the still unaccounted temperature deformation factor (drum shaft elongation), which leads to the disappearance of the thermal gap between the rings and rolling elements of the bearings decrease in the efficiency of the nodal seals. Conclusions. 1. The established dependence of the influence of the change and the difference in temperature of the constituent elements of the threshing apparatus unit on the durability of the bearings. It was found that when the difference between the temperatures of the bearing housings and the threshing drum shaft is more than 20 ° C, the thermal gap between its rings and the rolling elements disappears due to the thermal elongation of the drum shaft, which leads to the opening of the seal joints, and therefore to a decrease bearing life. A structural solution is proposed for the modernization of bearing assemblies, which achieves the leveling of the negative impact of thermal elongation of the shaft with minimized interventions in the base structure and associated material costs. A similar solution can be used in most agricultural machinery mechanisms, where, due to low rigidity or for other reasons, it is impossible to have a stable mutual arrangement of components rotating on bearings.

scholarly journals Effect of LPG Content on the Performance and Emissions of A Diesel-LPG Dual-Fuel Engine

1970 ◽  
Vol 46 (2) ◽  
pp. 195-200 ◽  
Author(s):  
GA Rao ◽  
AVS Raju ◽  
CVM Rao ◽  
KG Rajulu
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Agricultural Sector ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Engine Operation ◽  
Engine Load ◽  
Performance And Emission ◽  
Combustion Performance

In the present work, LPG, a by-product of petroleum refining process is used to replace conventional diesel fuel, partially, for improved combustion efficiency and clean burning. A conventional diesel engine was operated on the dual-fuel mode, using LPG as the primary fuel and diesel as the pilot fuel. A four-stroke, single-cylinder diesel engine, most widely used in agricultural sector, has been considered for the purpose of experimentation. The engine was operated at a constant speed of 1500 rpm at a low engine load of 20% and a high engine load of 80%. Under both these operating conditions, combustion, performance and emission characteristics of the engine have been evaluated and compared with that of baseline diesel fuel operation. At 20 % engine load the brake thermal efficiency of the engine has found to decrease with an increase in the LPG content. On the other hand at 80% engine load, it has increased with an increase in the LPG content. Same trend has been observed with regard to the mechanical efficiency. The volumetric efficiency has decreased with an increase in the LPG content at both the loads. The engine operation is more economical on dual-fuel operation at 80% engine load, whereas at 20% engine load, diesel fuel operation is found to be better. With regard to emissions, smoke density and emissions of NOx were found to reduce with an increase in LPG content at both the loads; however, emissions of HC and CO have shown the reverse trend. Key words: Dual-Fuel; LPG; Diesel; Combustion; Performance; Emissions Load. DOI: http://dx.doi.org/10.3329/bjsir.v46i2.8186 Bangladesh J. Sci. Ind. Res. 46(2), 195-200, 2011

The influence of the technical condition of the modernized spray on the service life of a nozzle sprayer of diesel engine

2020 ◽  
pp. 85-91
Author(s):  
Anzor L. Bolotokov ◽  
Valentin P. Lyalyakin
Keyword(s):  
Diesel Engine ◽  
Service Life ◽  
Diesel Engines ◽  
Resistance Coefficient ◽  
Technical Condition ◽  
Research Purpose ◽  
Spray Nozzle ◽  
Accelerated Tests ◽  
Spiral Groove ◽  
Discussion Article

Injectors of diesel engines lose their functionality due to loss of tightness and jamming of the needle of the nozzle sprayer. (Research purpose) The research purpose is increasing the durability of injectors by upgrading the sprayer needle by performing a spiral screw groove on its guiding part. (Materials and methods) The article notes that the screw groove is performed by an elbor cutter on a lathe with the following parameters: an angle of 30 degrees, a radius of 0.133 millimeters, and a length of 21.71 millimeters. Authors conducted research to determine the resistance coefficient of the gap between the sprayer body and the sprayer with a spiral groove, depending on the fuel contamination. Authors performed non-motor bench accelerated tests of sprayers to determine the hydraulic density, the volume of fuel in the screw groove, and the resistance coefficient of the gap. (Results and discussion) Article notes that the decrease rate in the value of hydro density in upgraded sprayers is 1.24 times less than in serial ones. The article shows that due to the screw groove, the needle of the sprayer is rotated, and the working surfaces of the needle are not caught with the sprayer body, which ensures uniform wear with less intensity. (Conclusions) Upgrading the spray nozzle by applying a screw groove to its surface ensures that the surfaces are lubricated and creates a softened twisting impact instead of a hard hit on the spray nozzle seat.

Heat Release Analysis of Oxygen-Enriched Diesel Combustion

1993 ◽  
Vol 115 (4) ◽  
pp. 761-768 ◽  
Author(s):  
D. Assanis ◽  
E. Karvounis ◽  
R. Sekar ◽  
W. Marr
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Oxygen Enrichment ◽  
Operating Conditions ◽  
Diesel Combustion ◽  
The Novel ◽  
Pressure Data ◽  
Engine Operation ◽  
Combustion Simulation ◽  
Release Analysis

A heat release correlation for oxygen-enriched diesel combustion is being developed through heat release analysis of cylinder pressure data from a single-cylinder diesel engine operating under various levels of oxygen enrichment. Results show that standard combustion correlations available in the literature do not accurately describe oxygen-enriched diesel combustion. A novel functional form is therefore proposed, which is shown to reproduce measured heat release profiles closely, under different operating conditions and levels of oxygen enrichment. The mathematical complexity of the associated curve-fitting problem is maintained at the same level of difficulty as for standard correlations. When the novel correlation is incorporated into a computer simulation of diesel engine operation with oxygen enrichment, the latter predicts pressure traces in excellent agreement with measured pressure data. This demonstrates the potential of the proposed combustion simulation to guide the application of oxygen-enriched technology successfully to a variety of multicylinder diesel systems.

Finite Element Investigation of a Piston Assembly of a Diesel Engine

2016 ◽  
Author(s):  
Mosfequr Rahman ◽  
Aniruddha Mitra ◽  
Sirajus Salekeen ◽  
Jeremy Buentello ◽  
Tyler Harden ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Diesel Engine ◽  
Entire System ◽  
Connecting Rod ◽  
Total Deformation ◽  
Element Analysis ◽  
Piston Head ◽  
Simulation Results ◽  
Piston Assembly

Ensure a safe, long life and efficient combustion within a diesel engine is an important challenge in the applications of engine technology. Much research has been done on thermal stress within engine cylinders and on engine piston heads, and how to reduce some of this stress in order to prevent failure or increase the life of the engine. The failure of a piston head tends to occur from it enduring the gas effect of the high pressures and temperatures. By performing static and dynamic Finite Element Analysis (FEA) on a piston mechanism of a diesel engine proper dimensions for different parts of an engine can be determined and failure of an engine in service can be avoided. In this research finite element analysis has been performed to determine the total deformation, stresses, and other parameters that are essential from design point of views. Real world input data for simulation obtained from running an existing diesel engine have been effectively used. Static structural and dynamic reaction of a piston assembly under the applied load of internal combustion in a diesel engine were closely observed. ANSYS workbench was utilized to perform these simulations. Using SolidWorks a piston assembly model consisting of the piston, connecting pin, connecting rod, cylinder head, crankshaft, and cranks was designed and used for simulation. Simulation results were being collected from the static structural and rigid body dynamics modules. The static structural simulation was conducted in order to obtain the structural response of the piston assembly under the combustion phase. This simulation was intended to replicate the pressure forces applied to the piston assembly at the moment of combustion. A pressure force of 7 MPa was applied to the top of the piston. From the simulation results, the maximum total deformation 1.9 mm occurred at the top edge of the piston head on the same side as the combustion chamber. Maximum equivalent Von Mises stress 323.9 MPa occurred at the joint of the connecting rod and crankshaft and the minimum equivalent stress 27 kPa occurred at the bottom of the connecting rod. Principal stresses were also examined, where the maximum principal stress 335.1 MPa occurred at the joint of the connecting rod and crankshaft and the minimum principal stress 63.5 MPa occurred inside of the connecting rod joint. The maximum shear stress 177.7 MPa occurred at the joint of the connecting rod and crankshaft and the minimum shear stress 14.26 kPa occurred at the bottom of the connecting rod. Two types of forces were considered acting upon the geometry in the rigid body dynamic simulation, one is standard earth gravity and the other is a linear dynamic load of 55,000 N applied to the top of the piston head which is used to simulate the act of combustion within the combustion chamber of a cylinder. From the rigid dynamic simulation, it was found that after the first combustion cycle, the linear velocity of the entire system, acceleration of the entire system, and the crank angular velocity reach to the maximum of 24.77 m/s, 17684 m/s2 and 5487 rpm respectively at 0.0187 seconds. Then after the second combustion cycle, the linear velocity of the entire system and the crank angular velocity reach to 27.56 m/s and 6043 rpm respectively at 0.0481 seconds; however the acceleration of the entire system took 0.0551 seconds to reach to 30115 m/s2.

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